U.S. patent application number 12/936467 was filed with the patent office on 2011-02-10 for thermoplastic elastomers.
This patent application is currently assigned to Evonik Degussa GmbH. Invention is credited to Ulrich Boes, Dieter Kuhn, Werner Michel, Uwe Schachtely, Mario Scholz, Andrea Tietze, Thomas Welker.
Application Number | 20110034590 12/936467 |
Document ID | / |
Family ID | 39691289 |
Filed Date | 2011-02-10 |
United States Patent
Application |
20110034590 |
Kind Code |
A1 |
Kuhn; Dieter ; et
al. |
February 10, 2011 |
THERMOPLASTIC ELASTOMERS
Abstract
Thermoplastic elastomer, which comprises a fumed, hydrophilic or
hydrophobic silica, which has been structurally modified and also a
process for the improvement of the mechanical properties of
thermoplastic elastomers. The thermoplastic elastomers are produced
by preparing a masterbatch from the components (e.g. thermoplastic
resin component and fumed silica) and compounding this with further
thermoplastic elastomers.
Inventors: |
Kuhn; Dieter; (Rodenbach,
DE) ; Michel; Werner; (Luetzelbach, DE) ;
Scholz; Mario; (Gruendau, DE) ; Schachtely; Uwe;
(Kahl am Main, DE) ; Welker; Thomas; (Hanau,
DE) ; Tietze; Andrea; (Frankfurt, DE) ; Boes;
Ulrich; (Frankfurt a.M., DE) |
Correspondence
Address: |
OBLON, SPIVAK, MCCLELLAND MAIER & NEUSTADT, L.L.P.
1940 DUKE STREET
ALEXANDRIA
VA
22314
US
|
Assignee: |
Evonik Degussa GmbH
Essen
DE
|
Family ID: |
39691289 |
Appl. No.: |
12/936467 |
Filed: |
March 24, 2009 |
PCT Filed: |
March 24, 2009 |
PCT NO: |
PCT/EP09/53404 |
371 Date: |
October 5, 2010 |
Current U.S.
Class: |
523/351 ;
524/263 |
Current CPC
Class: |
Y10T 428/2991 20150115;
Y10T 428/2995 20150115; C08K 3/36 20130101 |
Class at
Publication: |
523/351 ;
524/263 |
International
Class: |
C08J 3/22 20060101
C08J003/22; C08K 5/5415 20060101 C08K005/5415 |
Foreign Application Data
Date |
Code |
Application Number |
May 19, 2008 |
EP |
08156435.3 |
Claims
1. Thermoplastic A thermoplastic elastomer, comprising a
structurally modified hydrophilic or hydrophobic fumed silica.
2. The thermoplastic elastomer according to claim 1, wherein the
fumed silica has been hydrophobized by a surface-modifying agent or
a silane.
3. The thermoplastic elastomer according to claim 2, wherein the
fumed silica has been hydrophobized by dimethyldichlorosilane.
4. The thermoplastic elastomer according to claim 1, comprising
from 0.5 to 20% by weight of the structurally modified fumed
silica.
5. The thermoplastic elastomer according to claim 1, further
comprising an oil component.
6. The thermoplastic elastomer according to claim 1, further
comprising a styrene block copolymer, and also a thermoplastic
resin component.
7. A process for the production of the thermoplastic elastomer
according to claim 1, comprising compounding a proportion of the
fumed silica with a thermoplastic resin component to give a
masterbatch, and compounding the masterbatch, comprising fumed
silica and thermoplastic resin component with an additional amount
of the thermoplastic elastomer.
8. The process according to claim 7, wherein the masterbatch
comprises from 20 to 50 wt.-%, based on a total weight, of fumed,
structurally modified silica.
9. A process for improving mechanical properties of a thermoplastic
elastomer, the process comprising adding a hydrophilic or
hydrophobic fumed silica, which has been structurally modified, to
the thermoplastic elastomer.
10. The process according to claim 9, wherein the fumed silica is a
fumed silicon dioxide, hydrophobized with dimethyldichlorosilane,
and which has been structurally modified.
11. A process for improving tear resistance of a thermoplastic
elastomer, the process comprising adding a hydrophilic or
hydrophobic fumed silica, which has been structurally modified, to
the thermoplastic elastomer.
12. The process according to claim 11, wherein the fumed silica is
hydrophobic and has been hydrophobized with dimethyldichlorosilane
and has then been structurally modified.
13. The thermoplastic elastomer according to claim 2, comprising
from 0.5 to 20% by weight of the structurally modified fumed
silica.
14. The thermoplastic elastomer according to claim 3, comprising
from 0.5 to 20% by weight of the structurally modified fumed
silica.
15. The thermoplastic elastomer according to claim 1, comprising
from 4 to 14% by weight of the structurally modified fumed
silica.
16. The thermoplastic elastomer according to claim 2, comprising
from 4 to 14% by weight of the structurally modified fumed
silica.
17. The thermoplastic elastomer according to claim 3, comprising
from 4 to 14% by weight of the structurally modified fumed silica.
Description
[0001] The invention relates to thermoplastic elastomers.
[0002] Thermoplastic elastomers (abbreviated to TPE) are plastics
whose behaviour at room temperature is similar to that of
traditional elastomers but when heated can undergo plastic
deformation, therefore exhibiting thermoplastic behaviour.
[0003] Elastomers are usually three-dimensional-network molecules
chemically crosslinked into a wide-mesh structure. The crosslinking
cannot be reversed without destroying the material.
[0004] Some of the crosslinking points in thermoplastic elastomers
are physical (secondary-valence forces or crystallites), and these
separate on heating, without destroying the macromolecules. These
materials therefore have substantially better processability than
normal elastomers. By way of example, it is even possible to
re-melt and re-process waste materials from these plastics.
[0005] Thermoplastic elastomers are increasingly used in
traditional rubber applications, because cycle times for processing
are very short, since the process is similar to that for
plastics.
[0006] Other application sectors for thermoplastic elastomers are
retention systems for passengers in vehicles, examples being covers
for airbags, movable cable sleeves, etc.
[0007] Particular application sectors can use a thermoplastic
elastomer composed for example of SEEPS
(styrene-ethylene-ethylene/propylene-styrene) and PP
(poly-propylene).
[0008] Thermoplastic elastomers of this type can have the
disadvantage that although their transverse mechanical properties
(i.e. perpendicular to the direction of flow) do not alter or alter
only slightly, their longitudinal mechanical properties (i.e. along
the direction of flow) are relatively poor. This relationship can
also be reversed, depending on the formulation of the thermoplastic
elastomer.
[0009] It was therefore an object to produce thermoplastic
elastomers which have isotropic mechanical properties. Their
longitudinal and transverse mechanical properties are intended to
be identical or almost identical.
[0010] The invention provides a thermoplastic elastomer
characterized in that it comprises a hydrophobic or hydrophilic
fumed silica which has been structurally modified.
[0011] The hydrophobic fumed silica can have been hydrophobized by
means of a surface-modifying agent or by means of a silane.
[0012] A compound from the following list can be used as
surface-modifying agent or as silane: [0013] a) organosilanes of
the type (RO).sub.3Si (C.sub.nH.sub.2n+1) and (RO).sub.3Si
(C.sub.nH.sub.2n-1) [0014] R=alkyl, e.g. methyl, ethyl, n-propyl,
iso-propyl, butyl [0015] n=from 1 to 20 [0016] b) organosilanes of
the type R'.sub.x(RO).sub.ySi(C.sub.nH.sub.2n+1) and
R'.sub.x(RO).sub.ySi(C.sub.nH.sub.2n-1) [0017] R=alkyl, e.g.
methyl, ethyl, n-propyl, iso-propyl, butyl [0018] R'=alkyl, e.g.
methyl, ethyl, n-propyl, iso-propyl, butyl [0019] R'=cycloalkyl
[0020] n=from 1 to 20 [0021] x+y=3 [0022] x=1, 2 [0023] y=1, 2
[0024] c) haloorganosilanes of the type
X.sub.3Si(C.sub.nH.sub.2n+1) and X.sub.3Si (C.sub.nH.sub.2n-1)
[0025] X.dbd.Cl, Br [0026] n=from 1 to 20 [0027] d)
haloorganosilanes of the type X.sub.2 (R')Si (C.sub.nH.sub.2n+1)
and X.sub.2 (R')Si (C.sub.nH.sub.2n-1) [0028] X.dbd.Cl, Br [0029]
R'=alkyl, e.g. methyl, ethyl, n-propyl, iso-propyl, butyl [0030]
R'=cycloalkyl [0031] n=from 1 to 20 [0032] e) haloorganosilanes of
the type X(R').sub.2Si (C.sub.nH.sub.2n+1) and X (R').sub.2Si
(C.sub.nH.sub.2n-1) [0033] X.dbd.Cl, Br [0034] R'=alkyl, e.g.
methyl, ethyl, n-propyl, iso-propyl, butyl [0035] R'=cycloalkyl
[0036] n=from 1 to 20 [0037] f) organosilanes of the type
(RO).sub.3Si (CH.sub.2).sub.m--R' [0038] R=alkyl, e.g. methyl,
ethyl, propyl [0039] m=0, from 1 to 20 [0040] R'=methyl, aryl (e.g.
--C.sub.6H.sub.5, substituted phenyl radicals) [0041]
--C.sub.4F.sub.9, OCF.sub.2--CHF--CF.sub.3, --C.sub.6F.sub.13,
--O--CF.sub.2--CHF.sub.2 [0042] --NH.sub.2, --N.sub.3, --SCN,
--CH.dbd.CH.sub.2, --NH--CH.sub.2--CH.sub.2--NH.sub.2, [0043] --N--
(CH.sub.2--CH.sub.2--NH.sub.2).sub.2 [0044] --OOC(CH.sub.3)
C.dbd.CH.sub.2 [0045] --OCH.sub.2--CH(O)CH.sub.2 [0046]
--NH--CO--N--CO-- (CH.sub.2).sub.5 [0047] --NH--COO--CH.sub.3,
--NH--COO--CH.sub.2--CH.sub.3, --NH--(CH.sub.2).sub.3Si (OR).sub.3
[0048] --S.sub.x--(CH.sub.2).sub.3Si (OR).sub.3 [0049] --SH [0050]
--NR'R''R''' (R'=alkyl, aryl; R''.dbd.H, alkyl, aryl; R'''.dbd.H,
alkyl, aryl, benzyl, C.sub.2H.sub.4NR''''R''''', where R''''.dbd.H,
alkyl and R'''''.dbd.H, alkyl) [0051] g) organosilanes of the type
(R'').sub.x (RO).sub.ySi (CH.sub.2).sub.m--R''
[0051] R '' = alkyl = cycloalkyl ##EQU00001## x + y = 2
##EQU00001.2## x = 1 , 2 ##EQU00001.3## y = 1 , 2 ##EQU00001.4## m
= 0 , from 1 to 20 ##EQU00001.5## [0052] R'=methyl, aryl (e.g.
--C.sub.6H.sub.5, substituted phenyl radicals) [0053]
--C.sub.4F.sub.9, --OCF.sub.2--CHF--CF.sub.3, --C.sub.6F.sub.13,
--O--CF.sub.2--CHF.sub.2, [0054] --NH.sub.2, --N.sub.3, --SCN,
--CH.dbd.CH.sub.2, --NH--CH.sub.2--CH.sub.2--NH.sub.2, [0055]
--N--(CH.sub.2--CH.sub.2--NH.sub.2).sub.2 [0056]
--OOC(CH.sub.3)C.dbd.CH.sub.2 [0057] --OCH.sub.2--CH(O)CH.sub.2
[0058] --NH--CO--N--CO--(CH.sub.2).sub.5 [0059]
--NH--COO--CH.sub.3, --NH--COO--CH.sub.2CH.sub.3,
--NH--(CH.sub.2).sub.3Si (OR).sub.3 [0060]
--S.sub.x--(CH.sub.2).sub.3Si (OR).sub.3 [0061] --SH [0062]
--NR'R''R'''(R'=alkyl, aryl; R''.dbd.H, alkyl, aryl; R'''.dbd.H,
alkyl, aryl, benzyl, C.sub.2H.sub.4NR''''R''''', where R''''.dbd.H,
alkyl and R'''''.dbd.H, alkyl) [0063] h) haloorganosilanes of the
type X.sub.3Si (CH.sub.2).sub.m--R' [0064] X.dbd.Cl, Br [0065] m=0,
from 1 to 20 [0066] R'=methyl, aryl (e.g. --C.sub.6H.sub.5,
substituted phenyl radicals) [0067] --C.sub.4F.sub.9,
--OCF.sub.2--CHF--CF.sub.3, --C.sub.6F.sub.13,
--O--CF.sub.2--CHF.sub.2 [0068] --NH.sub.2, --N.sub.3, --SCN,
--CH.dbd.CH.sub.2, --NH--CH.sub.2--CH.sub.2--NH.sub.2 [0069]
--N--(CH.sub.2--CH.sub.2--NH.sub.2).sub.2 [0070]
--OOC(CH.sub.3)C.dbd.CH.sub.2 [0071] --OCH.sub.2--CH(O)CH.sub.2
[0072] --NH--CO--N--CO--(CH.sub.2).sub.5 [0073]
--NH--COO--CH.sub.3, --NH--COO--CH.sub.2--CH.sub.3,
--NH--(CH.sub.2).sub.3Si(OR).sub.3 [0074]
--S.sub.x--(CH.sub.2).sub.3Si(OR).sub.3 [0075] --SH [0076] i)
haloorganosilanes of the type (R)X.sub.2Si (CH.sub.2).sub.m--R'
[0077] X.dbd.Cl, Br [0078] R=alkyl, e.g. methyl, ethyl, propyl
[0079] m=0, from 1 to 20 [0080] R'=methyl, aryl (e.g.
--C.sub.6H.sub.5, substituted phenyl radicals) [0081]
--C.sub.4F.sub.9, --OCF.sub.2--CHF--CF.sub.3, --C.sub.6F.sub.13,
--OCF.sub.2--CHF.sub.2 [0082] --NH.sub.2, --N.sub.3, --SCN,
--CH.dbd.CH.sub.2, --NH--CH.sub.2--CH.sub.2--NH.sub.2, [0083]
--N--(CH.sub.2--CH.sub.2--NH.sub.2).sub.2 [0084]
--OOC(CH.sub.3)C.dbd.CH.sub.2 [0085] --OCH.sub.2--CH(O)CH.sub.2
[0086] --NH--CO--N--CO--(CH.sub.2).sub.5 [0087]
--NH--COO--CH.sub.3, --NH--COO--CH.sub.2--CH.sub.3,
--NH--(CH.sub.2).sub.3Si(OR).sub.3, where R can be methyl, ethyl,
propyl, butyl [0088] --S.sub.x--(CH.sub.2).sub.3Si(OR).sub.3, where
R can be methyl, ethyl, propyl, butyl, [0089] --SH [0090] j)
haloorganosilanes of the type (R).sub.2XSi(CH.sub.2).sub.m--R'
[0091] X.dbd.Cl, Br [0092] R=alkyl [0093] m=0, from 1 to 20 [0094]
R'=methyl, aryl (e.g. --C.sub.6H.sub.5, substituted phenyl
radicals) [0095] --C.sub.4F.sub.9, --OCF.sub.2--CHF--CF.sub.3,
--C.sub.6F.sub.13, --O--CF.sub.2--CHF.sub.2 [0096] --NH.sub.2,
--N.sub.3, --SCN, --CH.dbd.CH.sub.2,
--NH--CH.sub.2--CH.sub.2--NH.sub.2, [0097] --N--
(CH.sub.2--CH.sub.2--NH.sub.2).sub.2 [0098]
OOC(CH.sub.3)C.dbd.CH.sub.2 [0099] --OCH.sub.2--CH(O)CH.sub.2
[0100] --NH--CO--N--CO-- (CH.sub.2).sub.5 [0101]
--NH--COO--CH.sub.3, --NH--COO--CH.sub.2--CH.sub.3,
--NH--(CH.sub.2).sub.3Si(OR).sub.3 [0102]
--S.sub.x--(CH.sub.2).sub.3Si(OR).sub.3 [0103] --SH [0104] k)
silazanes of the type
[0104] ##STR00001## [0105] R=alkyl, vinyl, aryl [0106] R'=alkyl,
vinyl, aryl [0107] l) cyclic polysiloxanes of the type D 3, D 4, D
5, where D 3, D 4 and D 5 are cyclic polysiloxanes having 3, 4 or 5
units of the type --O--Si(CH.sub.3).sub.2--. For example,
octamethylcyclotetrasiloxane=D 4
[0107] ##STR00002## [0108] m) polysiloxanes or silicone oils of the
type
[0108] ##STR00003## [0109] m=0, 1, 2, 3, . . . .infin. [0110] n=0,
1, 2, 3, . . . .infin. [0111] u=0, 1, 2, 3, . . . .infin. [0112]
Y.dbd.CH.sub.3, H, C.sub.nH.sub.2n+1 n=1-20 [0113] Y.dbd.Si
(CH.sub.3).sub.3, Si(CH.sub.3).sub.2H Si(CH.sub.3).sub.2OH,
Si(CH.sub.3).sub.2(OCH.sub.3) Si (CH.sub.3).sub.2
(C.sub.nH.sub.2n+1) n=1-20 [0114] R=alkyl, e.g. C.sub.nH.sub.2n+1,
where n=from 1 to 20, aryl, e.g. phenyl and substituted phenyl
radicals, (CH.sub.2).sub.n--NH.sub.2, H [0115] R'=alkyl, e.g.
C.sub.nH.sub.2n+1, where n=from 1 to 20, aryl, e.g. phenyl and
substituted phenyl radicals, (CH.sub.2).sub.n--NH.sub.2, H [0116]
R''=alkyl, e.g. C.sub.nH.sub.2n+1, where n=from 1 to 20, aryl, e.g.
phenyl and substituted phenyl radicals, (CH.sub.2).sub.n--NH.sub.2,
H [0117] R'''=alkyl, e.g. C.sub.nH.sub.2n+1, where n=from 1 to 20,
aryl, e.g. phenyl and substituted phenyl radicals,
(CH.sub.2).sub.n--NH.sub.2, H.
[0118] The invention also provides a thermoplastic elastomer
characterized in that it comprises, as filler, a fumed silica which
has been hydrophobized by dimethyldichlorosilane and structurally
modified.
[0119] Fumed silicas which have been hydrophobized by
dimethyldichlorosilane and have been structurally modified are
known from U.S. Pat. No. 6,193,795.
[0120] A ball mill or a continuously operating ball mill can be
used for the structural modification process.
[0121] During the structural modification process, the agglomerate
structure of the fumed silica is mostly destroyed.
[0122] After the structural modification process, the DBP number is
lower, or impossible to determine.
[0123] The inventive thermoplastic elastomer can moreover comprise
an oil component and also components such as stabilizers.
[0124] Block copolymers and elastomer alloys are distinguished on
the basis of internal structure.
[0125] Block copolymers have hard and soft segments within one
molecule. The plastic is therefore composed of one type of
molecule, comprising areas corresponding to the two properties
(examples being SBS, SIS).
[0126] Elastomer alloys are polymer blends, i.e. mixtures of
finished polymers, and the plastic is therefore composed of more
than one type of molecule. Tailored materials are obtained through
differing mixing ratios and additives (an example being polyolefin
elastomer composed of polypropylene (PP) and natural rubber (NR).
These materials cover a wide range of hardness, depending on the
ratio of quantities).
[0127] Within thermoplastic elastomers a distinction is made
between the following groups: [0128] TPE-O or TPO=thermoplastic
elastomers based on olefin, mainly PP/EPDM, e.g. Santoprene
(AES/Monsanto). A thermoplastic elastomer referred to as a simple
blend (physical blend) which can be obtained by uniformly mixing an
elastomeric component with a thermoplastic resin. [0129] TPE-V or
TPV=crosslinked thermoplastic elastomers based on olefin, mainly
PP/EPDM, e.g. Sarlink (DSM). A TPV is also a thermoplastic
elastomer referred to as a simple blend (physical blend) which can
be obtained by uniformly mixing an elastomeric component with a
thermoplastic resin like a TPO. When the elastomeric component is
also crosslinked during mixing, a thermoplastic elastomer known in
the art as thermoplastic vulcanizate (TPV) results. Typically, a
TPV is formed by a process known as dynamic vulcanization, wherein
the elastomer and the thermoplastic matrix are mixed and the
elastomer is cured with the aid of a crosslinking agent and/or
catalyst during the mixing process. Since the crosslinked
elastomeric phase of a TPV is insoluble and non-flowable at
elevated temperature, TPVs generally exhibit improved oil and
solvent resistance as well as reduced compression set relative to
the simple blends.
[0130] The term "thermoplastic vulcanizate composition" (also
referred to as simply thermoplastic vulcanizate or TPV) is broadly
defined as any material that includes a dispersed, at least
partially vulcanized, rubber component; a thermoplastic resin
component; and an additive oil. A TPV material can further include
other ingredients, other additives, or both. The term "vulcanized"
is defined herein in its broadest sense, as reflected in any issued
patent, printed publication, or dictionary, and refers in general
to the state of a composition after all or a portion of the
composition (e.g., crosslinkable rubber) has been subjected to some
degree or amount of vulcanization is "dynamic vulcanization",
discussed below, which also produces a "vulcanizate". Also, in at
least one specific embodiment, the term vulcanized refers to more
than insubstantial vulcanization, e.g., curing (crosslinking) that
results in a measurable change in pertinent properties, e.g., a
change in the melt flow index (MFI) of the composition by 10% or
more (according to any ASTM-1238 procedure). In at least that
context, the term vulcanization encompasses any form of curing
(crosslinking), both thermal and chemical that can be utilized in
dynamic vulcanization.
[0131] The term "dynamic vulcanization" means vulcanization or
curing of a curable rubber blended with a thermoplastic resin under
conditions of shear at temperatures sufficient to plasticize the
mixture. In at least one embodiment, the rubber is simultaneously
crosslinked and dispersed as micro-sized particles within the
thermoplastic resin component. Depending on the degree of cure, the
rubber and thermoplastic resin component ratio, compatibility of
the rubber and thermoplastic resin component, the kneader type and
the intensity of mixing (shear rate), other morphologies, such as
co-continuous rubber phases in the plastic matrix, are
possible.
[0132] The "rubber component" can be any material that is
considered by persons skilled in the art to be a "rubber",
preferably crosslinkable rubber (e.g., prior to vulcanization) or
crosslinked rubber (e.g., after vulcanization). For example, the
rubber component can be any olefin-containing rubber such as
ethylene-propylene copolymers (EPM), including particularly
saturated compounds that can be vulcanized using free radical
generators such as organic peroxides, as noted in U.S. Pat. No.
5,177,147. Other rubber components can include
ethylene-propylene-diene (EPDM) rubber, or EPDM-type rubber, for
example. An EPDM-type rubber can terpolymer derived from the
polymerization of at least two different monoolefin monomers having
from 2 to 10 carbon atoms, preferably 2 to 4 carbon atoms, and at
least one polyunsaturated olefin having from 5 to 20 carbon
atoms.
[0133] A list of preferred rubber components include, but are not
limited to, ethylene-propylene-diene rubber, natural rubber, butyl
rubber, halobutyl rubber, halogenated rubber copolymer of
-alkylstyrene and at least one isomonoolefin having 4 to 7 carbon
atoms, a copolymer of isobutylene and divinylbenzene, a rubber
homopolymer of a conjugated diene having from 4 to 8 carbon atoms
and a vinyl aromatic monomer having from 8 to 12 carbon atoms, or
acrylonitrile monomer, or an alkyl substituted acrylonitrile
monomer having from 3 to 8 carbon atoms, or an unsaturated
carboxylic acid monomer, or an unsaturated anhydride of a
dicarboxylic acid, or combinations thereof.
[0134] The polyolefinic thermoplastic resin can be any material
that is not a "rubber" and that is a polymer or polymer blend
considered by persons skilled in the art as being thermoplastic in
nature, e.g., a polymer that softens when exposed to heat and
returns to its original condition when cooled to room temperature.
The polyolefinic thermoplastic resin component can contain one or
more polyolefins, including polyolefin homopolymers and polyolefin
copolymers. Except as stated otherwise, the term "copolymer" means
a polymer derived from two or more monomers (including terpolymers,
tetrapolymers, etc.), and the term "polymer" refers to any
carbon-containing compound having repeat units from one or more
different monomers.
[0135] Illustrative polyolefins can be prepared from mono-olefin
monomers including, but are not limited to, monomers having 2 to 7
carbon atoms, such as ethylene, propylene, 1-butene, isobutylene,
1-pentene, 1-hexene, 1-octene, 3-methyl-1-pentene,
4-methyl-1-pentene, 5-methyl-1-hexene, mixtures thereof and
copolymers thereof with (meth)acrylates and/or vinyl acetates.
Preferably, the polyolefinic thermoplastic resin component is
unvulcanized or non-crosslinked. [0136] TPE-U or TPU=thermoplastic
elastomers based on urethane, e.g. Desmopan (Bayer) [0137] TPE-E or
TPC=thermoplastic copolyester, e.g. Hytrel (DuPont) [0138] TPE-S or
TPS=styrene block copolymers (SBS, SEBS, SEPS, SEEPS and MBS), e.g.
Septon (Kuraray) [0139] TPE-A or TPA=thermoplastic copolyamides,
e.g. PEBA
[0140] Elastomers that can be used for TPE-S or for TPO/TPV are:
[0141] SEPS, SEEPS styrene-ethylene-propylene-styrene [0142] SEBS
styrene-ethylene-butylene-styrene [0143] SIS
styrene-isoprene-styrene [0144] SBS styrene-butadiene-styrene
[0145] EPDM ethylene-propylene-diene rubber [0146] EPM
ethylene-propylene rubber [0147] IIR isoprene-isobutylene rubber
[0148] EVA ethyl-vinyl acetate [0149] NR natural rubber
[0150] Mixtures of the abovementioned rubbers can also be used.
[0151] Thermoplastics that can be used for TPE-S or for TPO/TPV
are:
Most particularly preferred among these thermoplastic polymers are
polyolefins, such as polypropylene, polyurethanes, polyethylene,
high-density polyethylene, low-density polyethylene, polyamides,
such as nylon-6 and nylon-6,6, PVC, PET and blends and copolymers
based on these polymers. [0152] ABS acrylonitrile-butadiene-styrene
[0153] ASA acrylonitrile-styrene-acrylate [0154] EP
ethylene-propylene [0155] ETFE ethylene-tetrafluoroethylene [0156]
EVAC ethylene-vinyl acetate [0157] EVOH ethylene-vinyl alcohol
[0158] FEP tetrafluoroethylene-hexafluoropropylene ionomer [0159]
MABS methylmethacrylate-acrylonitrile-butadiene-styrene [0160] MBS
methacrylate-butadiene-styrene [0161] PA polyamide [0162] PA 6
polyamide 6 [0163] PA 11 polyamide 11 [0164] PA 12 polyamide 12
[0165] PA 66 polyamide 66 [0166] PA 610 polyamide 610 [0167] PA 612
polyamide 612 high temperature resistant polyamides [0168] PB
polybutene [0169] PBT polybutene terephthalate [0170] PC
polycarbonate [0171] PCTFE polychlorotrifluoroethylene [0172] PE
polyethylene [0173] HDPE high density polyethylene [0174] HMW-HDPE
high molecular weight high density polyethylene [0175] UHMW-HDPE
ultra high molecular weight high density polyethylene [0176] LDPE
low density polyethylene [0177] LLDPE linear low density
polyethylene [0178] VLDPE very low density polyethylene [0179] MDPE
medium density polyethylene [0180] PE-C chlorinated polyethylene
[0181] PET polyethylene terephthalate [0182] PFA perfluoro alkoxyl
alkane [0183] PIB polyisobutylene [0184] PMMA polymethyl
methacrylate [0185] PMMI poly-N-methyl-methacrylamide [0186] POM
polyoxymethylene [0187] PP polypropylene [0188] PP-B polypropylene
impact copolymers [0189] PP-H polypropylene homopolymers [0190]
PP-R polypropylene random copolymers [0191] PPE polyphenylene ether
[0192] PS polystyrene [0193] EPS expandable polystyrene [0194] HIPS
high impact polystyrene [0195] PTFE polytetrafluoroethylene [0196]
PVAC polyvinyl acetate [0197] PVAL polyvinyl alcohol [0198] PVC
polyvinyl chloride [0199] PVC-C chlorinated polyvinyl chloride
[0200] PVDC polyvinylidene chloride [0201] PVDF polyvinylidene
fluoride [0202] SAN styrene-acrylonitrile [0203] SB
styrenebutadiene [0204] SMAH styrene-maleic anhydride
tetrafluoro-ethylene-hexafluoropropylene-vinylidene fluoride [0205]
VC copolymers of vinyl chloride biodegradable plastics
[0206] The inventive thermoplastic elastomer TPE can comprise,
alongside the filler, by way of example, an oil component, a
polyolefinic thermoplastic resin component and a styrene block
copolymer.
[0207] Styrene Block Copolymers: The SBC thermoplastics and
thermoplastic elastomers useful in the invention can be block
copolymers of styrene/conjugated diene/styrene, with the conjugated
diene optionally being fully or partially hydrogenated, or mixtures
thereof. Generally this block copolymer may contain 10 to 50 weight
%, more preferably 25 to 35 weight % of styrene and 90 to 50 weight
%, more preferably 75 to 35 weight % of the conjugated diene, based
on said block copolymer. Most preferred, however, is a block
copolymer which contains 28 to 35 weight % of styrene and 68 to 72
weight % of the conjugated diene. The conjugated diene is selected
from butadiene, isoprene or mixtures thereof. Block copolymers of
the styrene/conjugated diene/styrene types can be SBS, SIS, SIBS,
SEBS and SEPS and SEEPS block copolymers.
[0208] These block copolymers useful are known in the art, and are
further described in Canadian Patent 2,193,264 and in International
Patent Applications WO 96/20248, WO 96/23823, WO 98/12240 and WO
99/46330. They are generally prepared by butyl lithium initiated
sequential anionic polymerization, but coupling of living S-B/S
diblocks or bifunctional initiation are also known methods--see, in
general, Thermoplastic Elastomers (2.sup.nd Ed.), Ch. 3, G. Holden,
N. Legge et al. (Hanser Publishers, 1996)--see US
2006/0220272).
[0209] The oil component can be: paraffinic (white oils),
naphthenic, or aromatic mixtures of the oils mentioned
(characterized via proportion of paraffins, naphthenes, aromatics,
viscosity). Viscosity range: low to high viscosity, e.g. from 1 to
1300 mm.sup.2/s at 40.degree. C.
[0210] The polyolefinic thermoplastic component can be any material
which is not a "rubber", and which is a polymer or polymer blend
which is regarded by the person skilled in the art as being of
thermoplastic type, for example a polymer which softens when it is
exposed to heat, and which returns to its original state when it is
cooled to room temperature. The polyolefinic thermoplastic
component can comprise one or more polyolefins, inclusive of
polyolefin homopolymers and polyolefin copolymers. Unless otherwise
stated, the expression "copolymer" means a polymer derived from two
or more monomers (inclusive of terpolymers, tetrapolymers, etc.),
and the expression "polymer" refers to any carbon-containing
compound which has repeat units of one monomer or of more than one
different monomer.
[0211] Examples of polyolefins can be produced from monoolefin
monomers including inter alia the following: monomers having from 2
to 7 carbon atoms, e.g. ethylene, propylene, 1-butene, isobutylene,
1-pentene, 1-hexene, 1-octene, 3-methyl-1-pentene,
4-methyl-1-pentene, 5-methyl-1-hexene, mixtures of the same and
copolymers of the same with (meth)acrylates and/or with vinyl
acetates. The polyolefinic thermoplastic resin component is
preferably non-vulcanized or non-crosslinked.
[0212] In one or more embodiments, the polyolefinic thermoplastic
component comprises polypropylene. The expression "polypropylene"
as used herein means in the broad sense any polymer regarded by the
person skilled in the art as a "polypropylene" (as presented in at
least one patent or one publication), and includes homopolymers,
impact-resistant polymers and random terpolymers of propylene. The
polypropylene used in the compositions described herein preferably
has a melting point higher than 110.degree. C., and includes at
least 90% by weight of propylene units and contains isotactic
sequences of such units. The polypropylene can also include atactic
sequences or syndiotactic sequences, or both. The polypropylene can
also include substantially syndiotactic sequences, so that the
melting point of the polypropylene is higher than 110.degree. C.
The polypropylene can derive either exclusively from propylene
monomers (i.e. those having only propylene units) or mainly from
propylene (more than 80% of propylene), where the remainder derives
from olefins, in particular ethylene and/or C.sub.4-C.sub.10
.alpha.-olefins. As found herein, certain polypropylenes have a
high MFI (e.g. from low values of 10, 15 or 20 g/10 min up to high
values of from 25 to 30 g/10 min). Others have a relatively low
MFI, e.g. "partial" polypropylenes whose MFI is less than 1.0.
Those with high MFI can be preferred because of easy processing or
easy compounding.
[0213] In one or more embodiments, the polyolefinic thermoplastic
component is isotactic polypropylene or includes the same. The
polyolefinic thermoplastic component comprises one or more
crystalline propylene homopolymers or propylene copolymers whose
melting point is above 105.degree. C., as measured by DSC.
Preferred propylene copolymers comprise, without being restricted
to these materials, propylene homopolymers or propylene
terpolymers, impact-resistant propylene copolymers, random
polypropylene and mixtures of the same. Preferred comonomers have 2
carbon atoms or from 4 to 12 carbon atoms. The comonomer is
preferably ethylene.
[0214] These polyolefinic thermoplastic components and processes
for the production of the same are described in the U.S. Pat. No.
6,342,565.
[0215] The expression "random polypropylene" as used herein means
in general terms a single-phase propylene copolymer with up to 9%
by weight, preferably 2% by weight and 8% by weight, of an
.alpha.-olefin comonomer. Preferred .alpha.-olefin comonomers have
2 carbon atoms or from 4 to 12 carbon atoms. The .alpha.-olefin
comonomer is preferably ethylene.
[0216] The thermoplastic elastomer can contain the following
fillers and reinforcements: [0217] Carbon [0218] Graphite [0219]
Carbon black [0220] Spherical fillers [0221] Solid spherical
fillers [0222] Solid glass spheres [0223] Other mineral solid
spherical fillers [0224] Hollow spherical fillers [0225] Hollow
glass spheres [0226] Other mineral hollow spherical fillers [0227]
Conductive fillers [0228] Metal and metal oxides [0229] Metallic
fibres [0230] Metal oxides [0231] Metallic flakes [0232] Mineral
fillers [0233] Aluminium trihydroxide [0234] Barium sulphate [0235]
Calcium carbonate [0236] Natural calcium carbonate [0237]
Precipitated calcium carbonate [0238] Dolomite [0239] Silica [0240]
Natural silica [0241] Quartz [0242] Synthetic silica [0243]
Cristabolite [0244] Precipitated silica [0245] Pyrogenic silica
[0246] Fused silica [0247] Silicates [0248] Natural silicates
[0249] Feldspar [0250] Nepheline syenite [0251] Mica [0252] Kaolin
[0253] Calcined kaolin [0254] Slate [0255] Talc [0256] Wollastonite
[0257] Synthetic silicates [0258] Precipitated calcium silicate
[0259] Precipitated sodium aluminium silicate [0260] Silicon
carbide [0261] Synthetic fibres [0262] Aramid fibres [0263] Glass
fibres [0264] Carbon fibres [0265] Mineral fibres [0266] Polyamide
fibres [0267] Polyester fibres
[0268] The inventive thermoplastic elastomer can moreover comprise
flame retardants, such as phosphates, phosphorus, ammonium
polyphosphate, magnesium hydroxide, triphenyl phosphate, melamine
cyanurate, expandable graphite, dipentaerythritol.
[0269] The thermoplastic matrix or compound can contain other
additives like: [0270] antifogging agents [0271] antistatic agents
[0272] biocides [0273] dispersants [0274] compatibilizers [0275]
pigment dispersants [0276] fragrances [0277] air release agents
[0278] colorants [0279] dyes [0280] pigments [0281] inorganic
pigments [0282] white pigments [0283] carbon black [0284] coloured
inorganic pigments [0285] organic pigments [0286] special colorants
[0287] flame retardants [0288] inorganic flame retardants [0289]
organic flame retardants [0290] halogen-free flame retardants
[0291] halogenated flame retardants [0292] brominated flame
retardants [0293] chlorinated flame retardants [0294] lubricants
and related auxiliaries [0295] lubricants [0296] antiblocking
agents [0297] antislip agents [0298] slip agents [0299] coupling
agents [0300] silanes [0301] titanates [0302] zirconates [0303]
initiators [0304] organic peroxides [0305] flatting agents [0306]
nucleating agents [0307] nucleating agents for foams [0308] optical
brighteners [0309] impact modifiers [0310] stabilizers [0311]
antioxidants [0312] light stabilizers [0313] metal deactivators
[0314] PVC stabilizers [0315] acid acceptors [0316] chemical
blowing agents [0317] processing aids [0318] processing aids (PVC)
[0319] processing aids (polyolefins) [0320] antisetting agents
[0321] mould release agents [0322] low profile additives [0323]
thixotropic agents [0324] viscosity regulators [0325] crosslinking
agents [0326] plasticizers
[0327] The inventive thermoplastic elastomer can comprise from 0.5
to 20% by weight, preferably from 4 to 14% by weight, of fumed,
structurally modified silica.
[0328] The silica can be added in powder form.
[0329] In one variant of the inventive process, which can also be
preferred, the fumed silica can first be used to produce a
masterbatch with the thermoplastic component, preferably with the
polypropylene component, which can then be blended with other
formulation constituents of the thermoplastic elastomer of the
SEEPS component.
[0330] The invention also provides a masterbatch composed of the
thermoplastic component and of fumed silica.
[0331] Another preferred subject matter of the invention is a
masterbatch composed of polypropylene and of fumed silica which has
been hydrophobized by means of dimethyldichlorosilane, and which
has been structurally modified.
[0332] The masterbatch can comprise an amount of up to 50%,
preferably 40%, based on the total weight, of the fumed
hydrophobized silica. However, it should comprise at least 20% by
weight, preferably at least 32% by weight, of fumed, structurally
modified silica.
[0333] The masterbatch can also comprise the oil components.
[0334] The invention also provides a process for the improvement of
the mechanical properties of thermoplastic elastomers, which is
characterized in that a fumed structurally modified silica is added
to the thermoplastic elastomers.
[0335] In one embodiment of the invention, a hydrophilic fumed,
structurally modified silica can be added.
[0336] In one embodiment of the invention, a hydrophobic fumed,
structurally modified silica can be added.
[0337] In another embodiment, a fumed hydrophobic silica is used
which has been hydrophobized by means of a surface-modifying agent
or by means of a silane.
[0338] Another preferred subject matter of the invention is a
process for the improvement of the mechanical properties of
thermoplastic elastomers, which is characterized in that a fumed
silica hydrophobized by means of dimethyldichlorosilane is added to
the thermoplastic elastomers.
[0339] The fumed silica hydrophobized by means of
dimethyldichlorosilane is known from DE 11 63 784. The fumed silica
AEROSIL R972 can preferably be used.
[0340] In particular, the inventive process can improve the tear
resistance along and across the direction of flow of the
thermoplastic elastomer.
[0341] The invention also provides the use of a fumed silica for
the improvement of the tear resistance of thermoplastic elastomers
TPE.
[0342] In one embodiment of the invention, a hydrophilic fumed,
structurally modified silica can be added.
[0343] In one embodiment of the invention, a hydrophobic fumed,
structurally modified silica can be added.
[0344] In another embodiment of the invention, a hydrophobic fumed
silica can be added which has been hydrophobized by means of a
surface agent or by means of a silane.
[0345] Another preferred subject matter of the invention is the use
of a fumed silica which has been hydrophobized by means of
dimethyldichlorosilane, for the improvement of the tear resistance
of thermoplastic elastomers TPE.
[0346] In particular, the fumed silica which has been hydrophobized
by means of dimethyldichlorosilane can be used for the improvement
of the tear resistance longitudinally and transversely with respect
to the direction of flow of thermoplastic elastomers TPE.
[0347] The fumed silica which has been hydrophobized by means of
dimethyldichlorosilane can also be used for the improvement of the
elongation at break, in particular in the longitudinal
direction.
[0348] The invention also provides the use of a fumed silica which
has been hydrophobized by means of dimethyldichlorosilane and has
then been structurally modified, for the improvement of the
mechanical properties of thermoplastic elastomers.
[0349] The fumed silica which has been hydrophobized by means of
dimethyldichlorosilane can have been structurally modified
according to U.S. Pat. No. 6,193,795.
[0350] The fumed silica AEROSIL R9200 can preferably be used. It is
known from WO 2004/020532. A silanized, structurally modified fumed
silica which has groups fixed to the surface can equally be used,
where these are dimethyl silyl and/or monomethyl silyl groups. They
are known from DE 102 39 423 A1. The definition of the term
"structurally modified" here is as stated above.
[0351] The inventive thermoplastic elastomers, and also the
inventive masterbatches, can be produced in known apparatuses, for
example in an extruder.
[0352] The inventive thermoplastic elastomers have isotropic
mechanical properties.
[0353] The inventive thermoplastic elastomers have improved thermal
and mechanical properties. In particular in the longitudinal
direction, the inventive thermoplastic elastomers have improved
tear resistance, and tensile strength, and also improved elongation
at break. The material likewise has improved heat resistance.
[0354] The inventive thermoplastic elastomer has almost isotropic
mechanical properties.
[0355] The inventive thermoplastic elastomer can be used in
automobile interiors, to increase high-temperature lightfastness
for automobile-interior applications, as sealing profile for
glass-backing applications in automobile construction and in
building, and also in automobile construction and electrical
engineering for gaskets in the region of lamps, preference being
given to applications involving dynamic stress.
[0356] The improved tear resistance permits use of the inventive
thermoplastic elastomer for the production of babies' dummies.
EXAMPLES
Production of the Compounded Materials
[0357] The compounding process took place on a co-rotating, tightly
intermeshing ZSE 27 Maxx twin-screw extruder from Leistritz.
[0358] The dry blends (composed of premix+thermoplastic) were
produced in a high-speed mixer and introduced to the extruder
through the main feed.
[0359] The premix is composed of 100 parts of SEEPS
(styrene-ethylene-ethylene/propylene-styrene). A mixture composed
of 100 parts of white oil and of 30 parts of polypropylene
homopolymer (PPh) is added.
[0360] Four silicas were used as filler for the examples:
[0361] KS1: Fumed silica hydrophobized by dichlorodimethylsilane
and based on a hydrophilic starting material whose surface area is
130 m.sup.2/g (AEROSIL R 972 V).
[0362] KS2: Fumed silica hydrophobized by dichlorodimethylsilane
and based on a hydrophilic starting material whose surface area is
200 m.sup.2/g. A structural modification process was also
undertaken after the hydrophobization (AEROSIL R 9200).
[0363] KS3: Fumed hydrophilic silica whose surface area is 150
m.sup.2/g (AEROSIL 150).
[0364] KS4: Fumed silica hydrophobized by polydimethylsiloxane and
based on a hydrophilic starting material whose surface area is 150
m.sup.2/g (AEROSIL R 202 VV 90).
[0365] Tables 1 to 4 list the physico-chemical data for the fumed
silica used.
TABLE-US-00001 TABLE 1 AEROSIL .RTM. R 972 V Compacted hydrophobic
fumed silica AEROSIL .RTM. R 972 V is a compacted fumed silica
which has been hydrophobized by DDS (dimethyldichlorosilane), and
is based on hydrophilic fumed silica whose specific surface area is
130 m.sup.2/g. Physico-chemical data: Guideline Properties Unit
values Specific surface area (BET) m.sup.2/g 110 .+-. 20 C content
% by weight 0.6-1.2 Average size of primary Nm 16 particles
Compacted bulk density g/l about 90 (approx. value)* by analogy
with DIN ISO 787/11, August 1983 Loss on drying* % by weight
.ltoreq.0.5 2 h at 105.degree. C. Loss on ignition, 2 h at % by
weight .ltoreq.2.0 1000.degree. C., based on the dried substance (2
h at 105.degree. C.) pH 3.6-4.4 4% strength dispersion SiO.sub.2
content, based on the % by weight .gtoreq.99.8 substance after
ignition *ex plant
TABLE-US-00002 TABLE 2 AEROSIL .RTM. R 9200 Hydrophobic fumed
silica AEROSIL .RTM. R 9200 is a structurally modified hydrophobic
fumed silica. Physico-chemical data: Guideline Properties Unit
values Specific surface area (BET) m.sup.2/g 170 .+-. 20 C content
% by weight 0.7-1.3 Compacted bulk density g/l about 200 (approx.
value)* by analogy with DIN EN ISO 787/11, August 1983 Loss on
drying* % by weight .ltoreq.1.5 2 h at 105.degree. C. pH 3.0-5.0 4%
strength dispersion SiO.sub.2 content, based on the % by weight
.gtoreq.99.8 substance after ignition Al.sub.2O.sub.3 content % by
weight .ltoreq.0.10 Fe.sub.2O.sub.3 content % by weight
.ltoreq.0.01 TiO.sub.2 content % by weight .ltoreq.0.03 HCl content
% by weight .ltoreq.0.025 *ex plant
TABLE-US-00003 TABLE 3 AEROSIL .RTM. 150 Hydrophilic fumed silica
AEROSIL .RTM. 150 is a hydrophilic fumed silica whose specific
surface area is 150 m.sup.2/g. Physico-chemical data: Guideline
Properties Unit values Specific surface area (BET) m.sup.2/g 150
.+-. 15 Average size of primary Nm 14 particles Compacted bulk
density g/l about 50 (approx. value)* by analogy with DIN ISO
787/11, August 1983 Loss on drying* % by weight .ltoreq.0.5 2 h at
105.degree. C. Loss on ignition, 2 h at % by weight .ltoreq.1.0
1000.degree. C., based on the dried substance (2 h at 105.degree.
C.) pH 3.7-4.7 4% strength dispersion SiO.sub.2 content, based on
the % by weight .gtoreq.99.8 substance after ignition *ex plant
TABLE-US-00004 TABLE 4 AEROSIL .RTM. R 202 VV 90 Compacted
hydrophobic fumed silica AEROSIL .RTM. R 202 VV 90 is a compacted
fumed silica which has been hydrophobized by polydimethylsiloxane
and is based on hydrophilic fumed silica whose specific surface
area is 150 m.sup.2/g. Physico-chemical data: Guideline Properties
Unit values Specific surface area (BET) m.sup.2/g 100 .+-. 20 C
content % by weight 3.5-5.0 Average size of primary Nm 14 particles
Compacted bulk density g/l about 90 (approx. value)* by analogy
with DIN ISO 787/11, August 1983 Loss on drying* % by weight
.ltoreq.0.5 2 h at 105.degree. C. Loss on ignition, 2 h at % by
weight 4.0-6.0 1000.degree. C., based on the dried substance (2 h
at 105.degree. C.) pH 3.6-4.4 4% strength dispersion SiO.sub.2
content, based on the % by weight .gtoreq.99.8 substance after
ignition *ex plant
[0366] The filler (fumed silica) can be added in two different
ways: [0367] 1. It can be added directly in powder form. For this,
a proportion of up to 4% of filler is added to the premixes. The
further amounts of filler were conveyed through a separate feed
gravimetrically into the melt, using an ancillary side feeding
extruder. [0368] 2. The filler is added by means of a masterbatch,
where the fumed silica has first been mixed with the polypropylene
homopolymer.
[0369] The masterbatch/polypropylene homopolymer (PP-h) was added
to the high-speed mixer after preparation of the premixes, thus
producing a dry blend. The content of thermoplastic (polypropylene
homopolymer) needed in the entire formulation must remain the same,
and is partially replaced by the polypropylene homopolymer present
in the masterbatch.
TABLE-US-00005 TABLE 5 Extruder parameters: Extruder settings
Rotation rate, rpm 350 Throughput, kg/h 10-15 Barrel temp.,
.degree. C. 180-200 Specified values Melt temp., .degree. C.
170-190 Melt pressure, bar >20
Injection Moulding
[0370] All of the compounded materials were used to produce plaques
whose dimensions were 150 mm.times.100 mm.times.2 mm, in
conventional injection-moulding processes (for which the machine
parameters can be found in Table 6.
TABLE-US-00006 TABLE 6 Settings for 2 mm plaque Cylinder
temperature, .degree. C. 180-200 Peripheral velocity of screw,
140-150 mm/sec Back pressure, bar 40-50 Injection rate, % 65-70
Hold-pressure time, sec. 5-25 Hold pressure, bar 280-500 Mould
temperature, .degree. C. 30-35 Cooling time 5-20
[0371] The following tests were carried out on the plaques of the
compounded materials: [0372] Shore A hardness test to DIN 53 505
[0373] determination of ultimate tensile strength, tensile
strength, elongation at break and stress values in the tensile
test, longitudinal/transverse, to DIN 53 504, S2 specimen [0374]
longitudinal/transverse tear resistance, to DIN 53 515 (DIN 350
34-1), angled specimen [0375] heat-ageing*.sup.1 to DIN 350 815
[0376] *.sup.1=test of mechanical properties after heat-ageing:
[0377] The test specimens were stamped out from the
injection-moulded plaques. The film gate at the side of the plaque
causes orientation of the flow of the melt. The orientation of the
flow leads to anisotropic properties of the plaque. In order to
discern the effect of hot-air ageing on anisotropy, the specimens
were stamped out from the plaques respectively longitudinally and
perpendicularly to the orientation of flow.
[0378] The specimens were aged at 150.degree. C. in a convection
oven. After 3 days, and also after 7 days, some of the specimens
were removed from the oven and aged for 24 h under standard
conditions (23.degree. C., 50% rel. humidity). The tests were then
carried out according to the abovementioned standards.
Example 1
[0379] A compounded TPE-S material was produced according to the
instructions described above.
[0380] The loading level of fumed silica filler was varied from 1
to 8%, and the material here was added directly in powder form.
[0381] Mechanical properties (longitudinal and tranverse) were
compared with the unfilled compounded TPE-S material.
TABLE-US-00007 TABLE 7 LONGITUDINAL results: Longitudinal
Longitudinal Compression tensile elongation set (24 h Hardness
strength at break 75.degree. C.) [Shore A] [MPa] [%] [%] Reference
58 3.3 233 37 1% KS 1 56 3.3 265 36 2% KS 1 56 3.5 320 38 4% KS 1
62 4.7 435 37 8% KS 1 68 7.0 529 44
[0382] Surprisingly, it has been found that the use of the fumed
silica KS1 in TPE-S materials could raise the tensile strength and
elongation at break (determined longitudinally) by 112%/127%, while
advantageously the compression set could be held at the same
level.
TABLE-US-00008 TABLE 8 TRANSVERSE results: Transverse Transverse
Compression tensile elongation set (24 h Hardness strength at break
75.degree. C.) [Shore A] [MPa] [%] [%] Reference 58 12.4 855 37 1%
KS 1 56 12.0 845 36 2% KS 1 56 12.8 837 38 4% KS 1 62 15.3 847 37
8% KS 1 68 17.6 820 44
[0383] Tensile strength improved with increasing amount of fumed
silica KS1, while the use of the fumed silica KS1 causes hardly any
change in the elongation at break (determined transversely), when
comparison is made with the reference.
[0384] The two elongation-at-break tables (longitudinal &
transverse) show a novel and very important advantage of the
inventive thermoplastic elastomer in relation to the use of fumed
silica in TPE-S. By virtue of the marked increase in longitudinal
elongation at break and the very small alteration in transverse
values for elongation at break, the longitudinal & transverse
values for elongation at break become closer as the amount used of
fumed silica KS1 increases. That means that the isotropy within the
injection-moulded TPE-S part is markedly improved, and that the
subsequent component produced from the inventive thermoplastic
elastomer has higher dimensional stability.
Example 2
[0385] A compounded TPE-S material is produced according to the
instructions described above.
[0386] The loading level of fumed silica filler is 12%. The fumed
silica KS1 was added directly in powder form. Mechanical properties
(longitudinal and tranverse) were compared with the unfilled
compounded TPE-S material.
TABLE-US-00009 TABLE 9 Longitudinal tear Transverse tear resistance
resistance [N/mm] [N/mm] Reference 19 16 12% KS 1 40 30
[0387] Surprisingly, it has been found that the use of 12% of fumed
silica KS1 can raise the longitudinal/transverse tear resistance in
TPE-S by approximately .about.111%/.about.88%.
Example 3
[0388] Specimens were stamped out from the injection-moulded TPE-S
plaques produced in Example 1 with 8% filler content, and also the
reference, and these were subjected to heat-ageing.
[0389] Mechanical properties (longitudinal and tranverse) were
compared with the unfilled compounded TPE-S material.
TABLE-US-00010 TABLE 10 Longitudinal/transverse tensile strength
results: Change in longitudinal tensile strength 0 days 3 days 7
days MPa MPa Change % MPa Change % Reference 3.3 2.8 -15.2 2.9
-12.1 8% KS 1 7.0 9.8 40.0 10.2 45.7
[0390] Surprisingly, it has been found that the use of 8% of fumed
silica KS1 in the compounded TPE-S material can raise the tensile
strength (determined longitudinally) after 7 days of heat-ageing at
150.degree. C. by .about.46%, when comparison is made with the
initial value, while tensile strength of the reference falls by
.about.10% after 7 days of ageing.
[0391] The tensile strength values (determined transversely) remain
at the same level despite heat-ageing.
TABLE-US-00011 TABLE 11 Longitudinal/transverse elongation at break
results: Change in longitudinal elongation at break 0 days 3 days 7
days % % Change % % Change % Reference 320 222 -30.6 223 -30.3 8%
KS 1 529 740 39.9 759 43.5
[0392] Surprisingly, it has been found that the use of 8% of fumed
silica KS1 in the compounded TPE-S material can raise the
elongation at break (determined longitudinally) after 7 days of
heat-ageing at 150.degree. C. by .about.44%, when comparison is
made with the initial value, while the tensile strength of the
reference falls by .about.30% after 7 days of ageing.
[0393] The elongation at break values (determined transversely)
remain at the same level despite heat-ageing.
[0394] As described above in Example 1, the use of the fumed silica
KS1 markedly improves isotropy.
[0395] The heat-ageing additionally improves the elongation at
break value (longitudinal) by .about.44% for the TPE-S with 8% of
filler, while the elongation at break measured transversely remains
at the same level. This also gives an additional marked improvement
in isotropy when comparison is made with non-aged TPE-S
plaques.
Example 4
[0396] A compounded TPE-S material is produced according to the
instructions described above.
[0397] The loading level of fumed silica filler KS1 is 8%. The
fumed silica KS 2 was added in the form of a polypropylene/fumed
silica masterbatch. Mechanical properties (longitudinal and
transverse) were compared with the unfilled compounded TPE-S
material.
TABLE-US-00012 TABLE 12 LONGITUDINAL results: Longitudinal
Longitudinal Compression tensile elongation set (24 h Hardness
strength at break 75.degree. C.) [Shore A] [MPa] [%] [%] Reference
58 3.3 233 37 8% KS 2 61 10.7 713 40 via masterbatch
[0398] Surprisingly, it has been found that the use of the fumed
silica KS 2 in the compounded TPE-S materials could raise the
tensile strength and elongation at break (determined
longitudinally) by 224%/206%, while the compression set and, unlike
in Example 1, also the hardness, could advantageously be held at
the same level.
TABLE-US-00013 TABLE 13 TRANSVERSE results: Transverse Transverse
Compression tensile elongation set (24 h Hardness strength at break
75.degree. C.) [Shore A] [MPa] [%] [%] Reference 58 12.4 870 37 8%
KS 2 61 17.6 841 40 via masterbatch
[0399] Tensile strength is improved with increasing amount of the
fumed silica, while the use of the fumed silica produces only an
insignificant change in the elongation at break (determined
transversely) when comparison is made with the reference.
[0400] The important advantage of the use of the fumed silica in
TPE-S resulting from the two tables with the results for elongation
at break (longitudinal & transverse) is the same as previously
shown in Example 1. The isotropy, and therefore the dimensional
stability, of the subsequent component is markedly increased.
[0401] Surprisingly, it has been found that addition of the fumed
silica KS 2 via masterbatch markedly increases the overall level of
mechanical properties.
[0402] When the silica is added by means of masterbatch, the silica
becomes distributed in the system in the elastomer phase, in the
interface and in the thermoplastic. The result is that the silica
acts to some extent as compatibilizer.
Example 5
[0403] Specimens were stamped out from the injection-moulded
[0404] TPE-S plaques produced according to Example 4 with 8% filler
content, and also the reference, and these were subjected to
heat-ageing. Mechanical properties (longitudinal and transverse)
were compared with the unfilled compounded TPE-S material.
TABLE-US-00014 TABLE 14 Results for longitudinal tensile strength:
Change in longitudinal tensile strength 0 days 3 days 7 days MPa
MPa Change % MPa Change % Reference 3.3 2.8 -15.2 2.9 -12.1 8% KS 2
via 10.7 15.3 43.0 15.4 43.9 masterbatch
[0405] Surprisingly, it has been found that the use of 8% of the
fumed silica KS 2 in the compounded TPE-S material could raise the
tensile strength (determined longitudinally) after 7 days of
heat-ageing at 150.degree. C. by .about.44%, when comparison is
made with the initial value, while the tensile strength of the
reference after 7 days of ageing fell by .about.12%.
TABLE-US-00015 TABLE 15 Longitudinal/transverse elongation at break
results: Change in longitudinal elongation at break 0 days 3 days 7
days % % Change % % Change % Reference 320 222 -30.6 223 -30.3 8%
KS 2 via 713 790 10.8 811 13.7 masterbatch
[0406] Surprisingly, it has been found that the use of 8% of the
fumed silica KS 2 in the compounded TPE-S material could raise the
elongation at break (determined longitudinally) after 7 days of
heat-ageing at 150.degree. C. by .about.14%, when comparison is
made with the initial value, while the tensile strength of the
reference after 7 days of ageing fell by .about.30%.
[0407] The values for elongation at break (determined transversely)
remain at the same level, despite heat-ageing.
[0408] As previously described in Example 4, the use of the fumed
silica KS 2 markedly improved isotropy. The heat-ageing
additionally gave an improvement of .about.14% in the
(longitudinal) value for elongation at break of the TPE-S with 8%
of filler, while the elongation at break measured transversely
remained at the same level. This also markedly improved isotropy
when comparison was made with un-aged TPE-S plaques. As likewise
previously described in Example 4, mechanical properties were at a
very high level by virtue of the fumed silica KS 2 and the addition
via masterbatch. The result in Example 5 was almost complete
elimination of the anisotropy of the TPE-S.
Example 6
[0409] A compounded TPE-S material is produced according to the
instructions described above.
[0410] The loading level of fumed silica filler is 4%, added
directly in powder form.
[0411] Mechanical properties (longitudinal and transverse) were
compared with the unfilled compounded TPE-S material.
Longitudinal & Transverse Results:
TABLE-US-00016 [0412] Longitudinal Longitudinal Compression tensile
elongation set (24 h Hardness strength at break 75.degree. C.)
[Shore A] [MPa] [%] [%] Reference 58 3.3 233 37 4% KS 3 63 4.1 343
41
TABLE-US-00017 Transverse Transverse Compression tensile elongation
set (24 h Hardness strength at break 75.degree. C.) [Shore A] [MPa]
[%] [%] Reference 58 12.4 855 37 4% KS 3 63 16.0 853 41
[0413] Surprisingly, it has been found that the use of the fumed
silica KS 3 in compounded TPE-S materials could raise tensile
strength and elongation at break (determined longitudinally) by
.about.24%/.about.47%, while advantageously the compression set was
altered only insignificantly. The possible improvement in
transverse tensile strength was .about.29%, whereas (transverse)
elongation at break remains unaltered.
[0414] By virtue of the improvement in (longitudinal) elongation at
break and the (transverse) elongation at break held at the same
level, the longitudinal & transverse elongation-at-break
properties become closer to one another, and this increases
dimensional stability in the subsequent component.
Example 7
[0415] A compounded TPE-S material is produced according to the
instructions described above.
[0416] The loading level of fumed silica filler was varied from 1
to 4%, and the material here was added directly in powder form.
[0417] Mechanical properties (longitudinal and tranverse) were
compared with the unfilled compounded TPE-S material.
Longitudinal & Transverse Results:
TABLE-US-00018 [0418] Longitudinal Longitudinal Compression tensile
elongation set (24 h Hardness strength at break 75.degree. C.)
[Shore A] [MPa] [%] [%] Reference 58 3.3 233 37 1% KS 4 59 3.7 370
37 2% KS 4 58 4.0 442 37 4% KS 4 57 4.3 542 38
TABLE-US-00019 Transverse Transverse Compression tensile elongation
set (24 h Hardness strength at break 75.degree. C.) [Shore A] [MPa]
[%] [%] Reference 58 12.4 855 37 1% KS 4 59 12.7 847 37 2% KS 4 58
14.1 850 37 4% KS 4 57 14.0 855 38
[0419] Surprisingly, it has been found that the use of the fumed
silica KS 4 in compounded TPE-S materials could raise the tensile
strength and elongation at break (determines longitudinally) by
.about.30%/.about.133%, while the compression set and the hardness
of the compounded TPE-S materials advantageously remained
unaltered. The possible improvement in transverse tensile strength
was .about.29%, whereas (transverse) elongation at break remains
unaltered.
[0420] By virtue of the marked improvement in (longitudinal)
elongation at break and the (transverse) elongation at break held
at the same level, the longitudinal & transverse
elongation-at-break properties become closer to one another, and
this increases dimensional stability in the subsequent
component.
* * * * *